'Rawlemon' may be the future of the solar panel

The Rawlemon's orb concentrates diffused light onto a photovoltaic panel which moves as it tracks the sun. Andre Broessel says it is 35 per cent more efficient than regular panel arrays

Duncan Nicholls

In 2010, German architect Andre Broessel wanted to fit a building in Düsseldorf with solar panels -- but he ran into a problem: "There was not enough roof space for conventional panels, and on the façade the tilt losses would be too great," he says.

Then, one sunny Sunday morning, Broessel watched his daughter put a marble into an eggcup. "I played around with it and noticed how the focal point moved in the rounded surface." This insight led to the Rawlemon, a solar panel born from Broessel's belief that "we can squeeze more juice from the Sun".

Regular solar panels often can't make the most of the sunshine because they're in the shade, or only receiving weak, reflected light. After its initial 180-centimetre-tall Beta.ray proof of concept (pictured), which generates up to 3.4kWh a day, Broessel is now producing a range of ten-centimetre-tall solar chargers for phones, called Beta.ey. The plan is to "make concentrated photovoltaics popular", then scale it up: he is also developing a "MicroTrack power module" to fit as a near-transparent skin for buildings, aiming to generate up to 150W per square metre. "This will change the market," he claims. More power to him.

This article was first published in the May 2014 issue of WIRED magazine